As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HF RADIO #2 UNABLE TO TRANSMIT. GENERATES PROLONGED TUNE-TONE EACH TIME PTT IS PRESSED. TRIED FROM BOTH SEATS AND ON MULTIPLE FREQUENCIES WITH SAME EFFECT; REMOVED AND REPLACED HF #2 TRANSCEIVER PER AMM 23-11-33 PB 401. BITE TEST OK. THIS CLEARS MDDR 522304. MX-4 UPDATED.